This photograph was taken a few seconds before the soldiers fired. It indicates the soldiers were in good order, showing no signs of confusion and disarray.
The soldiers also don't seem to be in any imminent danger -- which is the only reason why soldiers are allowed to fire upon a crowd.
The photgraph shows that the soldiers' apparently orchestrated preparations to fire are bordering on criminal. The group of students in the foreground (who may seem to be the most significant threat to the soldiers) are being entirely overlooked. Indeed, the only student who became a casualty in this picture is the student on the left side on the far side of the iron rail, standing with his back to the camera.
He was shot twice. At the time, he was making an obscene gesture at the soldiers.